Airplane propeller



Bea. 16, 1930. F. A. DUMONT AIRPLANE PROPELLER Filed March 5, 1928 WGWEY Patented l 316, i230 WK A. EDONT, GE SHELTQN, WMINGTON BPLANE PROPELLER Application filed March 5,

The objects of my invention, generally stated, are, to provide an airplane propeller which, in its broader aspect, 1s cylindrical 1n form and of hollow construction, the same 5 having a plurality of blades pro ectmg outwardly and inwardly, with air'passages disposed therebetvqeen, through whlch a partial vacuum is produced within the propeller and the airplane is sustained in the a1r and propelled; to afford, in such a device, a comcal member located interiorly and centrally thereof: which reduces the resistanceof the air to the propeller when the airplaneis moving forwardly and also, cooperates with sald 1a passages in permitting air to be forced out of the propeller; and, to furnish, through these instrumentalities and their location in close proximity to the engine, highly efliclent means for directing air to the englne and the cooling thereof.

Uther objects will appear as the description of the invention progresses.

in the accompanying drawin Figure 1 is a view of an airp ane, broken an away, showing said propeller mounted thereon Fig. 2, a front elevation of the propeller, indicating means by which it is secured to the engine of the airplane;

Fig. .3, a side elevation of the propeller, the engine shaft bein broken away; and, n

Fig. 4, a CIOSSSGCUQB, drawn on the line H of Fig. 2.

Referring more particularly to the drawing, 1 designates the base of the device which carries on its outer side a flared and circumferentially extending section 2 and on its inner side a member, generally denoted as 3,

in the form of a truncated cone. Said mem- I v her is provided with a housin d for the free end of the engine shaft, and t e base thereof is formed into a portion thickened to add strength, as at 5, havin a plurality of openings 6 for securing a 5|. nge of the shait to the base.

1928. Serial N0. 259,177.

A series of blades 10 are disposed across and extend completely around the propeller, the blades being located in spaced parallel relation, and diagonally in the direction of its normal .path of rotation. Each blade also extends interiorly of the propeller, the portion thus extending being denoted as 11,- and inclined as indicated in Fig. 2, its inner end connecting With said cone.

A plurality of inclined sections 12, disposed in spaced parallel relation, extend between all the blades and give the propeller the appearance of what might be termed a cell-like construction. They afiord, in cooperation with the base, supports for the blades and provide, in connection with the blades, a rigid structure having a comparatively large number of air passages 13 through which air may be expelled from the propeller when it is rotating. As it may be noted in Fig. 3, those of said sections 12 located in the front of the propeller are. placed slightly back of the forward terminals of the blades, as at 14, obviously for the pur ose of enlarging the area of the free bla e surfaces thereat.

To the airplane 20, having the engine 21 provided with a shaft 22 terminating at its outer end in a threaded section 23 and equipped with a-flange 24, the propeller is secured in operative position by said shaft bein disposed inthe housing 4i of the conical rnem er, the nut securing it to the housing being denoted as 25, and the flange being fastened to the base by the bolts 26.

The device is designed to be made of metal and preferably of integral construction, but, as is evident, should it be deemed expedient to make it in several parts the same may be welded or secured together in any appropriate manner.

In operation, the rotary movement of the propeller permits it to perform in a measure the functions of the ordinary type of propeller, and in addition thereto the forcible ejection of air through the air passages between the blades imparts also a driving force to the propeller; the impingement of the air against the inner surfaces of the inclined sections 12 as it is thus ejected from the propeller creates a suspending power; and, said ejection also causes a partial vacuum to be formed within the propeller itself and directly in front of the engine, which are important contributing factors in sustaining and propelling the airplane in the air.

The base of the propeller, with its flared flange, is designed to and is so disposed relative to the engine as to protect it from air resistance, and the conical member obviously offers less resistance to the air in a forward movement of the airplane than would be afforded by the flat section of the base, and it also cooperates, through said movement, in the forcing of air from the propeller out through said passages, thereby contributing to the useful results ascribed thereto.

. embodiment of the invention, the propeller has a diameter somewhat less than that of the engine, and the pitch of the inclined sections 12 is such as to cause jets of air from the air passages to be forced directly to the cylinders of the engine for cooling purposes. Should it be deemed desirable to install such a propeller which is as large or larger in diameter than the engine, it will be obvious to those skilled in the art that simple means could be provided for diverting said jets of air to the engine.

While up or edge portions of the blades are shown as ush with the inclined sections 12 and the flared section 2, the spacin between the blades is made sufficiently wi e'to permit them to act efiectively on the air in performing their functions, and the inclined sections 11 of the blades, which extend below the sections 12, are designed to be of adequate width, relative to the other arts, for the purpose of forcing air outwardly of the propeller as described, however, it is evident that said portions and sections of the blades may beextended in width, or the pitch of the sections 12 varied, if thought expedient.

Other changes in and modifications ofthe construction describedmay be made without departing from the spirit of my invention or sacrificing its advantages, hence I ask that I be not confined to the specific structure set forth.

I claim:

1. An airplane propeller, comprising 'a base, a conical member extending from the base and integral therewith, an elongated bearing for a shaft extending through the base and the apex of the member, a plurality of blades extendin circumferentially of and enclosing the mem er, said blades bein disr posed in spaced parallel relation and do u ning a diagonal course in the direction of normal annularly and having; their inner ends. 56-

cured to the base, sai blades being disposed in spaced parallel relation and defining a diagonal course in the direction ofnormal rotation of the propeller, the outer edge portions of the blades being locatedin angular relation to the base and their inner edge portions inclined in the direction of normal rotation of the propeller, and a plurality of inclined sections extending between said por tions, disposed in spaced parallel relation and providing a plurality of air passages between the blades and bordering on saidflange adapted to discharge air from the side 0 the propeller in a direction to the rearwardly thereof.

3. An airplane propeller, comprising a base, a plurality of blades extending annularly and having their inner ends secured to the base, said blades being disposed in spaced parallel relation, the outer edge portions of the blades being located angularly relative to the base and their inner edge portions inclined in the direction of normal rotation of the propeller, and a plurality of sections extending between said portions, disposed in spaced parallel relation and providing a plur'ality of cell-like air passages between each blade and the adjacent blade adaptedto discharge air from the side of the propeller.

4. In .an airplane propeller, a plurality of blades annularly arranged, said blades being spaced apart, and a plurality ofsections disposed between adjacent blades in spaced parallel relation, providing supporting elements for the blades and a plurality of celllike air passages therebetween extending uninterruptedly throughout the outer circumferential area-of the propeller.

5*. In an airplane propeller, a base, and a plurality of spaced blades extending from the ase and disposed in cylindrical form, the spaces between said blades being provided with inclined cell-like air passages adapted,

for a pro eller shaft extending through the base mem er and the apex of the conical member, a plurality of bladessecured to the conical member and extendingb in cylindrical form beyond said apex said lades being disposed in spaced arallel relation and each having an inner e ge portion inclined in the direction of normal rotation of the propeller, and

a plurality of inclined sections extending between said blades and spaced apart'to provide a pluralit of cell-like air passages extending of the propeller.

- FRANK A. DUMONT;

throng out the circumferential area i 

